*{
    margin: 0;
    padding: 0;
}
#app {
    width: 500px;
    min-height: 100px;
    margin: 50px auto;
    border: 1px solid black;
    box-sizing: border-box;
    padding:0 10px;
    #app-top {
        display: flex;
        height: 50px;
        line-height: 50px;
        justify-content: space-between;
        font-size: 16px;
        #app-top-left {
            color: blue;
        }
        #app-top-right {
            color: tomato;
        }
    }
    #app-mid {
      textarea {
        width: 100%;
        font-size: 14px;
        text-indent: 16px;
        line-height: 16px;
      }
    }
  
    #app-bottom {
        display: flex;
        height: 50px;
        line-height: 50px;
        justify-content: space-between;
        align-items: center;
        font-size: 14px;
      #app-bottom-left {
        display: flex;
        section.bottom-left-item {
            width: 65px;
        }
      }
  
      #app-bottom-right {
        .title {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 70px;
            height: 30px;
            border-radius: 4px;
            background-color: tomato;
            color: white;

        }
      }
    }
  }